石鼓隧道开挖方法研究

发布时间：2018-05-24 20:36

本文选题：隧道 + CD法　；参考：《重庆交通大学》2015年硕士论文

【摘要】：本论文的研究以博罗石鼓隧道为依托,该隧道主体位于软弱围岩中,结合实际工程研究软弱围岩下隧道施工的方法,对今后类似的软岩隧道施工方法提供参考。论文主要根据隧道地质条件、水文地质条件以及各种地质资料,以数值模拟分析和现场监控量测相结合的手段,展开对隧道在施工过程中力学行为研究,通过有限元软件ANSYS模拟中隔壁法(以下简称CD法)和双侧壁导坑法开挖浅埋暗挖隧道,计算分析了围岩、初支应力及位移的力学性现象。具体成果如下:(1)岩性、岩体结构和裂隙、地应力、工程因素等都是影响软弱围岩下隧道结构稳定性的因素,而软弱围岩下隧道结构的破坏特征包括破坏方式多、变形量大、变形速度高、持续时间长、破坏范围大和位置不一等。破坏的模式包括掉块、膨胀破坏、挤压破坏、滑动破坏等。(2)根据依托工程实际地质情况,文中利用有限元软件ANSYS进行CD法和双侧壁导坑法的三维建模数值分析,通过计算数据分析可以得出围岩、初期支护的应力和位移值,对比规范并结合工程经验围岩、初期支护受力均低于强度规范值,都满足设计规范的强度要求;围岩、初期支护的位移变化均符合规范要求。根据计算结果,双侧壁导坑法对沉降的控制更为有效,其最终沉降值约为CD法的一半。初支的应力也较CD法小,偏向于安全。但两种方法的计算结果均符合《公路隧道设计规范》(JTG D70-2004)极限位移判断公路隧道拱顶沉降变形控制值要求。因此,本工程CD法和双侧壁导坑法均可以采用,但从工艺、成本、工期、经济学方面考虑,CD法优于双侧壁导坑法。(3)综合了各项因素考虑,CD法较双侧壁导坑法优势明显,是本工程中所选用的方法,其有利于大型机械施工,工序间相互影响较小,安全和经济性较为明显,对于快速施工意义重大。
[Abstract]:The research of this paper is based on the Bolo Shigu tunnel, which is located in the weak surrounding rock. Combining with the actual engineering, the paper studies the construction method of the tunnel under the soft rock, and provides a reference for the similar soft rock tunnel construction method in the future. According to the tunnel geological conditions, hydrogeological conditions and various geological data, the paper studies the mechanical behavior of the tunnel in the construction process by means of numerical simulation analysis and field monitoring and measurement. By using the finite element software ANSYS to simulate the shallow excavation tunnel by the adjoining wall method (CD method) and the double-side wall guide pit method, the mechanical phenomena of surrounding rock, initial support stress and displacement are calculated and analyzed. The concrete results are as follows: lithology, rock mass structure and fissure, in-situ stress, engineering factors and so on are all factors that affect the stability of tunnel structure under weak surrounding rock. The failure characteristics of tunnel structure under weak surrounding rock include many failure modes and large deformation. The deformation speed is high, the duration is long, the damage range is large and the position is different. The failure modes include mass drop, expansion failure, extrusion failure, sliding failure and so on. According to the actual geological conditions of the engineering, the 3D modeling numerical analysis of CD method and double-side wall guide pit method is carried out by using the finite element software ANSYS in this paper. Through the analysis of calculation data, the stress and displacement values of surrounding rock and initial support can be obtained. Compared with the code and combined with engineering experience surrounding rock, the initial support force is lower than the strength standard value, which all meet the strength requirements of the design code. The displacement changes of the initial support are in accordance with the requirements of the code. According to the calculation results, the method of double-side wall guide pit is more effective in controlling the settlement, and its final settlement value is about half of that of CD method. The stress of the initial branch is smaller than that of the CD method, and the stress is more safe than that of the CD method. However, the calculation results of the two methods are in line with the limit displacement of JTG D70-2004) for judging the control value of the settlement and deformation of the arch roof of the highway tunnel. Therefore, both the CD method and the double-side wall method can be used in this project, but in terms of technology, cost, time limit and economics, the CD method is superior to the double-side wall method in considering all factors, and the advantages of CD method are obvious than that of the double-side wall method. It is the method chosen in this project, which is beneficial to large-scale mechanical construction, with little interaction between working procedures, obvious safety and economy, and is of great significance for rapid construction.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U455.4

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